AD7862_15 Datasheet, PDF (4/16 Pages) Analog Devices – Simultaneous Sampling Dual 250 kSPS 12-Bit ADC

AD7862
TIMING CHARACTERISTICS1, 2 (VDD = +5 V ؎ 5%, AGND = DGND = 0 V, REF = Internal. All Specifications TMIN to TMAX unless
otherwise noted.)
Parameter
A, B
Versions
S
Version
Units
Test Conditions/Comments
t_CONV
3.6
t_ACQ
0.3
Parallel Interface
t₁
0
t₂
0
t₃
35
t₄
35
t₅₃
12
60
t₆₄
5
30
t₇
40
3.6
µs max
Conversion Time
0.3
us max
Acquisition Time
0
ns min
CS to RD Setup Time
0
ns min
CS to RD Hold Time
45
ns min
CONVST Pulse Width
45
ns min
Read Pulse Width
12
ns min
Data Access Time After Falling Edge of RD
70
ns max
5
ns min
Bus Relinquish Time After Rising Edge of RD
40
ns max
40
ns min
Time Between Consecutive Reads
NOTES
1_{Sample tested at +25°C to ensure compliance. All input signals are measured with tr = tf = 1 ns (10% to 90% of +5 V) and timed from a voltage level of +1.6 V.}
2 _{See Figure 1.}
3_{Measured with the load circuit of Figure 2 and defined as the time required for an output to cross 0.8 V or 2.0 V.}
4_{These times are derived from the measured time taken by the data outputs to change 0.5 V when loaded with the circuit of Figure 2. The measured number is then}
extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. This means that the times quoted in the timing characteristics are the true bus
relinquish times of the part and as such are independent of external bus loading capacitances.
Specifications subject to change without notice.
CONVST
BUSY
A0
t₃
t_CONV
CS
RD
DATA
.........
t₁
t₂
t₄
t₅
t₆
VA1
VA2
.........
t₇
VB1
V_B2
Figure 1. Timing Diagram
TO
OUTPUT
PIN
50pF
1.6mA
+1.6V
200µA
Figure 2. Load Circuit for Access Time and Bus Relinquish Time
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD7862 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
–4–
REV. 0